The present invention relates to sight gages and more particularly to an in-line sight indicator assembly for indicating the levels of dryness and excessive quantities of water in a refrigerant system and the presence of refrigerant.
Various types of indicators have been used in the past wherein an indicating element responds by color change to the presence of water in a predetermined range within a refrigerant system, attention being directed for example to long since expired U.S. Pat. Nos. 2,761,312, issued to Richard A. Line et al on Sep. 4, 1956 and 2,836,974, issued to Waiter O. Krause on Jun. 3, 1958. In these patents, the color and the color intensity change in response to the relative saturation of water in a liquid above or below a predetermined range level with the color change being reversible in response to reverse relative saturations. In addition various in-line sight indicator housing assemblies have been utilized to house the color responding indicator elements. For the most part, these in-line sight indicator housing assemblies have supported the color responding indicator element at a position above the flow axis of the fluid stream to be examined with the indicator element being substantially against the sight glass. Moreover, the housing assembly structures of the past usually have included a number of parts, being comparatively complex and expensive in manufacture and assembly and being occasionally prone to fluid and/or gas leakage at the various junctures of the several parts of the assembly. In FIG. 3 of the drawings described herein below, one such assembly similar to that sold by AMI of ALCO Controls Division, Emerson Electric Co., St. Louis, Mo. includes an internally threaded housing having an in-line flow cavity internally threaded and recessed to receive an externally threaded sleeve having a sight glass disposed therein with a spring-like legged spider member support which, in turn, is supported by the leg extremities nesting in an internal groove in the sleeve. The spring-like legged spider member has an indicator element receiving cup mounted at the apex, the spider member serving to urge the indicator element toward the inner face of the sight glass. In FIG. 4 of the hereinbelow described drawing, a housing assembly structure similar to those sold by the Sporlan Company of St. Louis, Mo. and the Superior Valve Co. of Washington, Pa. is shown as including an externally threaded male carrier post threadably engageable with an internally threaded aperture in a housing member having a flow-through cavity, the male carrier post, in turn nesting with a hollow female sleeve having an indicator element mounted at one end thereof which indicator element can be urged toward the inner face of a sight glass mounted in the housing wall opposite the internally threaded post receiving aperture. In FIG. 5 of the hereinbelow described drawings, a housing assembly structure similar to that sold by the Henry Valve Co. of Melrose Park, Ill. is shown as including an externally threaded nipple on a flow-through housing, the nipple serving to threadedly receive an internally threaded sleeve which has a sight glass mounted therein and is so hollowed to receive a color changing disc-like indicator ring sandwiched between a pair of gaskets with the sandwiched disc-like indicator ring being positioned substantially adjacent the inner face of the sight glass when the several disclosed parts are assembled.
From the above descriptions of the prior art, it readily can be seen that previous in-line sight indicators have included several comparatively complex and expensive to manufacture and assemble parts which have been prone to fluid leakage at the parts junctures and which have supported the indicator elements in spaced relation to the flow axis of the fluid stream to be observed.
The present invention provides an in-line sight indicator assembly which requires a minimum of parts, which is comparatively straight forward and inexpensive to manufacture and assemble, which is hermetically sealed to be comparatively free of fluid leakage and which has an indicator element positioned adjacent the flow axis of the fluid stream to be sampled to give a more accurate condition indicator.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.